package part3collection;

import java.util.Set;
import java.util.UUID;
import java.util.concurrent.CopyOnWriteArraySet;

public class SetTest01 {

    /**
     * CopyOnWriteArraySet解决HashSet的并发问题
     */
    public static void main(String[] args) {

        // 线程不安全
//        Set<String> set = new HashSet<>();

        // 线程安全
        Set<String> set = new CopyOnWriteArraySet();

        for (int i = 0; i < 30; i++) {
            new Thread(() -> {
                set.add(UUID.randomUUID().toString().substring(0, 8));
                System.out.println(set);
            }, String.valueOf(i)).start();
        }
    }

}
